* Arnd Bergmann <a...@arndb.de> wrote:
> > Do you really think that all of the 32-bit ARM code should
> > essentially be thrown away when going to 64-bit ARM, that
> > patches can only touch arch/arm64/ + drivers/ or the
> > highway?
>
> Yes.
Straight answer ;-)
> If you're curious, please have a look at
> arch/arm/mach-spear13xx/. this is the latest platform that we
> have added. [...]
Very nice.
> [...] It's fully functional (except PCI, which I hope will be
> added in drivers/pci/bus, which is another story), A
> significant portion of that platform deals with SMP support,
> which is being standardized for AArch64, so there will be only
> one implementation. Another big portion is DMA-engine support,
> which is moving out of arch/arm as soon as we have a proper DT
> binding. Finally there are some boilerplate header files that
> are going away too.
>
> Once we're done with this, we will basically need zero code in
> arch/*/ to support a new platform, and that is very easy to
> share between two distinct arch/* directories ;-)
Ok, arch specific platform code going away completely is a valid
solution - if you can pull that off for all new hardware then
arch/arm64/ might actually work.
The life time of ARM hw is also a lot shorter than on x86. Plus,
given that Apple and MS keeps Linux away from their hardware
cryptographically we only have to deal with hw makers who
specifically *want* Linux support. A lot of the maintenance pain
on x86 comes from the fact that Linux support on a lot of PC
hardware is incidental, from the hw maker's POV.
Ok, sounds like a valid plan. Just fix the name please :-)
Thanks,
Ingo
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